How to initial data for update form? about meteor-wizard HOT 8 CLOSED

// Template
{{> wizard id="productUpdate" steps=steps doc=data.........

// JS
Template.productUpdate.helpers({
    data: function () {
        var data = Collection.Product.findOne(this._id);
        return data;
    },

// Step
{#autoForm id="generalStep" schema=step.schema}}......
{{#autoForm id="loanAmountStep" schema=step.schema}}......
{{#autoForm id="chargStep" schema=step.schema}}......

// Template
{{> wizard id="productUpdate" steps=steps

// JS
Template.productUpdate.helpers({
 steps: function () {
        return [
            {
                id: 'general',
                title: 'General',
                template: 'generalStep',
                formId: 'generalStep',
                schema: Schema.Product.general,
                data: function () {
                    var data = Collection.Product.findOne(this._id);
                    return data;
                },
            },
             ..............................

            {
                id: 'charge',
                title: 'Charge',
                template: 'chargStep',
                formId: 'chargStep',
                schema: Schema.Product.charge,
                data: function () {
                    var data = Collection.Product.findOne(this._id);
                    return data;
                },
                onSubmit: function (data, wizard) {
                    var self = this;
                    var extend = _.extend(wizard.mergedData(), data);
                    // update doc
                }
            }
        ]
    }